The present invention relates to an air belt apparatus for use in a motor vehicle having an expanding portion provided in a seat belt webbing for occupant restraint.
An air belt apparatus for use in a motor vehicle is disclosed in Unexamined Japanese Patent Application Publication No. 2002-187514. In the air belt apparatus, a bag (expanding portion) of the air belt is housed in a mesh webbing (elastic cover) upon being folded back along a folding-back line, orthogonal to a longitudinal direction. Thereby, the bag of the air belt is prevented from passing through a belt guide (shoulder anchor). In addition, a length of the expanding portion (developing length) of the webbing (bag) is configured to be further elongated.
However, in the above-described example, although a developing length of the webbing can be elongated, the comfort of the webbing during normal operation can be improved. The comfort can be improved because a cover is constructed to retain a bag-shaped portion of the webbing in a belt-shaped manner by covering the bag-shaped portion of the webbing during normal operation. When the bag is expanded, the cover is configured to pass through a shoulder anchor.
In light of the aforementioned problems, an object of the present invention to improve the comfort of the webbing during normal operation by thinning a thickness of the webbing that passes through the shoulder anchor, and extending the developing length of an expanded portion of the bag upward, when the bag is expanded.